Fig. 1

Cell counts, expression and release of (pro-)inflammatory markers following exposure to CuO materials. BALB/c mice were sensitized ip to OVA/Alum on day 1 and 10, and exposed repeatedly to 2.5, 10 or 40 μg/mouse of CuO nanomaterials dispersed in PBS with or without OVA by oropharyngeal aspiration after a 10-day recovery period. a BAL cell counts showed the ability of CuO materials to trigger an increase in the number of macrophages, lymphocytes and especially neutrophils into the airways of both PBS- and OVA-challenged mice whereas eosinophils were detected only in OVA-challenged groups. b PAS staining revealed that CuO materials did not activate mucin-production in goblet cells. c Pro-inflammatory cytokines TNF and IL-33 were expressed in PBS-challenged as well as OVA-challenged mice while Th2 type cytokine IL-13 was expressed only in OVA-challenged mice. d IL-13 protein was detected in BAL supernatants by ELISA also only in OVA-challenged mice. Results in a-b are shown with the highest number of cells marked on top of each plot. Columns and error bars represent mean values ± standard error of mean (SEM). Statistically significant differences between experimental groups and PBS-challenged control mice are marked with “*” whereas the ones between experimental groups and OVA-challenged control mice are marked with “•”. */•P < 0.05; **/••P < 0.01; ***/•••P < 0.001. HPF, high power field; PAS, periodic acid–Schiff